Reitmayer, C. | Search bioRxiv

bioRxiv2021

Towards CRISPR/Cas9-based gene drive in the diamondback moth Plutella xylostella

Promising to provide powerful genetic control tools, gene drives have been constructed in multiple dipterans, yeast and mice, for the purposes of population elimination or modification. However, it remains unclear whether these techniques can be applied to lepidopterans. Here, we used endogenous regulatory elements to drive Cas9 and sgRNA expression in the diamondback moth, (Plutella xylostella), and test the first split-drive system in a lepidopteran. The diamondback moth is an economically important global agriculture pest of cruciferous crops and has developed severe resistance to various insecticides, making it a prime candidate for such novel control strategy development. A very high level of somatic editing was observed in Cas9/sgRNA transheterozygotes, although no significant homing was revealed in the subsequent generation. Although heritable, Cas9-medated germline cleavage, as well as maternal and paternal Cas9 deposition was observed, rates were far lower than for somatic cleavage events, indicating robust somatic but limited germline activity of Cas9/sgRNA under the control of selected regulatory elements. Our results provide valuable experience, paving the way for future construction of gene drive-based genetic control strategies in DBM or other lepidopterans.

genetics↗

bioRxiv2020

Sex, Age, and Parental Harmonic Convergence Behavior Affect the Immune Performance of Aedes aegypti Offspring

Aedes aegypti is an important vector of several pathogenic arboviruses including dengue, chikungunya and Zika. Innovative approaches to control Aedes populations, involving synthetic transgenic modifications as well as Wolbachia bacteria, appear promising. For the various techniques requiring offspring inheritance of a trait, released males must successfully compete for mating partners against wildtype males. However, very little is known about mechanisms of mate selection in mosquitoes in general and in particular about potential correlations between mating success and offspring immune performance. Harmonic convergence signals have been proposed as a cue for females to predict male quality. We investigated whether offspring of converging parental pairs showed differences in immune competence compared to offspring derived from non-converging parental pairs using three different types of immune assays. We found that offspring immune responses (melanization response and response to a bacterial challenge) differed between offspring from converging and non-converging parents. However, immune responses were shaped by several interacting factors such as sex, age, reproductive status, and parental mating behavior. Parental mating behavior had a stronger effect on the immune response of male offspring than on female offspring. Further, a population of female offspring derived from converging parental pairs reached their peak dengue virus dissemination rate earlier compared to a population of offspring derived from non-converging parental pairs. Our results provide insight into a wide range of selective pressures shaping mosquito immune function. Evolutionary trade-offs between naturally and sexually selected traits can have important implications for disease transmission and control and should be considered in the development of reproductive control strategies.

ecology↗